Impact of obesity on cancer therapy outcomes: a multicenter cohort study of 30-day mortality and morbidity.

Obesity is a substantial concern in oncology, influencing cancer characteristics and treatment outcomes. This study investigated whether obesity contributes to increased 30-day mortality and morbidity in patients receiving anticancer therapy. In this multicenter retrospective cohort study, patients with cancer were categorized as either normal weight or obese and analyzed based on demographics, cancer types, treatment modalities, and 30-day posttreatment mortality and morbidity rates. Statistical comparisons were performed to determine associations between obesity, treatment type, and clinical outcomes. Among 1635 patients, 46.6% ( n  = 760) were of normal weight and 53.4% ( n  = 875) were obese. Obesity was more prevalent among female patients, while 60.4% of male patients were of normal weight ( P  = 0.001). Substantial associations have been found between obesity and specific cancers, including colorectal cancer, lymphoma, head and neck cancer, and sarcoma. Chemotherapy was more frequently administered to patients with obesity (62.5%, P  = 0.001), while hormonal therapy was predominantly administered to patients with normal weight (81.8%). Patients with normal weight exhibited a higher 30-day mortality rate (74.5%, P  = 0.05), although morbidity rates did not differ substantially between the weight groups. Obesity is associated with specific cancer types and influences treatment selection, but it does not independently increase the incidence of short-term treatment complications. These findings suggest that the effect of obesity is more prominent in terms of cancer type and treatment choice than in predicting short-term morbidity. Further studies are warranted to elucidate the long-term effects of obesity on cancer outcomes.